@@ -57,7 +57,7 @@ def update_settings(default_settings, user_settings):
5757 # merge everything except the engines
5858 for k, v in user_settings.items():
5959 if k not in ('use_default_settings', 'engines'):
60− if k in default_settings:
60+ if k in default_settings and isinstance(v, Mapping):
6161 update_dict(default_settings[k], v)
6262 else:
6363 default_settings[k] = v